Supplementally is a word used to describe something that is in addition to something else. Synonyms for supplementally include additionally, extra, and furthermore. Other synonyms include in addition, moreover, further, and besides. These words are often used to provide further information or to clarify something that has been previously mentioned. They are also commonly used in academic or professional contexts, such as when presenting new research or data. Other synonyms for supplementally include secondary, supplementary, and complementary, which all suggest that something is helping to complete or add to a larger whole. Overall, there are many synonyms available for supplementally, each of which can be used to express a slightly different meaning or nuance.